Valve mechanism for controlling the flow of a plastic material for manufacturing and filling a plastic hollow body

ABSTRACT

A device for manufacturing and filling a plastic hollow body includes a hollow supporting sleeve for a hollow plastic blank which is to be blown up, and a valve in the sleeve cooperating with the free end of the sleeve. The sleeve is supported by a cylinder casing having a widened area defining an inlet chamber connected to an inlet for receiving the material to be filled into the hollow body and connected to the bore of the sleeve. The valve is operated by a control mechanism which is sealed from the inlet chamber by a diaphragm. The diaphragm carries an actuation member which is displaced by a control piston of the control mechanism to cause actuation of the valve at the free end of the supporting sleeve.

O United States Paten 11 1 1 1 3,726,325

Munz 51 Apr. 10, 1973 VALVE MECHANISM FOR 2,983,480 5/1961 Greenlie..74/18.2 x CONTROLLING THE FLOW OF A 1,651,773 12 1927 Jarvis.....251/63.4 x PLASTIC MATERIAL FOR 233383 131132? 332:3; "iii/282iMANUFACTURINGANDFHJLINGA y PLASTM: HOLLOW BODY Primary Examiner-HoustonS. Bell, Jr. [75] Inventor: Paul Munz, Netstal, Switzerland Att0meyMG1eWand Tore" [73] Assignee: Maschinenfabrik Und Giesserei Net- [57]ABSTRACT stal AG, Netstal, Switzerland A device for manufacturing andfilling a plastic hollow- [22] Filed: 1970 body includes a hollowsupporting sleeve for a hollow [21] APPL 93,162 plastic blank which isto be blown up, and a valve in the sleeve cooperating with the free endof the sleeve. The sleeve is supported by a cylinder casing having aU-S. Cl. widened area an inlet chamber connected to 92/168, 141/372,222/504, 239/ an inlet for receiving the material to be filled into thehollow body and connected to the bore of the sleeve. Cl "B676 B651) 53/0 The valve is operated by a control mechanism which is [58] Field ofSearch ..l8/5 BA; 53/140; l d fr th inl t chamber by a diaphragm. The

18.2; 9 317, diaphragm carries an actuation member which is displaced bya control piston of the control mechanism 63-6 to cause actuation of thevalve at the free end of the supporting sleeve. [56] References Cited 3Claims, 1 Drawing Figure UNITED STATES PATENTS 3,087,518 4/1963 Scholle..l4l/317 X SUMMARY OF THE INVENTION This invention relates in generalto the construction of filling control devices and, in particular, to anew and useful device for manufacturing and filling a plastic hollowbody having a valve operating mechanism with an operating control whichis sealed from the valve space.

It is known to produce hollow bodies from plastic by blowing up a hollowblank in a plastic state by means of the filling liquid and to fill itat the same time. With such a process, it is possible to pack sterileliquids as they are used, for example, in the pharmaceutical industryincluding such liquids as distilled water, salt and glucose solutions,etc. These materials are packed directly in plastic ampoules which aresealed during the manufacture and filling so that it is not necessary toprovide a subsequent sterilization thereof.

The blown-up and filled hollow bodies or ampoules are usually filled tothe brim, and this is not desirable, however, since the filling liquidcan spill over by the movements of the arrangement and the shrinking ofthe ampoules over a period of time until the neck becomes closed and iswelded shut. Another problem is that filling liquids which are used arecorrosive or highly reactive and they, therefore, should not come incontact with bearing and guide points of the operating mechanism.

In accordance with the invention, there is provided a hollow supportingsleeve for the hollow plastic blank which is to be blown-up. An interiorvalve member extends through the sleeve and the sleeve defines the flowpassage for the filling material. The valve shaft extends beyond thesleeve and into an enlarged filling chamber defined at the interior of acylindrical casing therefor. The valve is actuated by a controlmechanism which, in accordance with the invention, is separated in aliquidtight manner from the liquid feed inlet and the filling chamber.

With the inventive construction, it is possible to operate the valveindependently of the pressure conditions in the liquid feed duct and tokeep it open, particularly after the blank has been blown-up and thehollow body is filled in order to be able to draw back excess liquid. Inaddition, the control mechanism and its guides or working media, in thecase of a hydraulic or pneumatic device, are completely separated fromthe path of the filling liquid. This ensures a reduction of wear andsusceptibility to difficulties of operation and provides a sealingarrangement which is inexpensive. In addition, it also permits a freeselection of the most expedient control mechanism which can operate, forexample, mechanically, magnetically, hydraulically orpneumatically. Inpractice it was found particularly advantageous to provide aconstruction in which the valve shaft is not rigidly connected with theoperating means of the valve control mechanism. In order to separate theliquidfeed ducts from the control mechanism, it is advisable to providea diaphragm over which the con- I trol of the valve can be effected.

Accordingly, it is an object of the invention to provide an improvedfilling control mechanism for filling hollow bodies with a fluid whichincludes an inlet chamber connected to a filling passage through whichthe filling fluid is directed and which is closable by a valve; andwherein the valve is actuated by a control which is separated from thefilling passages in a sealed chamber.

A further object of the invention is to provide a device for fillinghollow plastic ampoules with a liquid which is directed into the ampouleunder the control of a valve member which is actuated by a controlmechanism operating through a sealing diaphragm.

A further object of the invention is to provide an operating valve forfilling small plastic bodies which is simple in design, rugged inconstruction and economical to manufacture.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference should be had to the accompanying drawing and descriptivematter in which there is illustrated a preferred embodiment of theinvention.

BRIEF DESCRIPTION OF THE DRAWING The only FIGURE of the drawing is alongitudinal sectional view of a filling mechanism with a control valveconstructed in accordance with the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawingin particular, the invention embodied therein comprises a device forfilling small plastic hollow bodies such as ampoules and which includesa cylindrical casing 4 which is clamped vertically in a supporting plate1 by a pair of nuts 2 which are threaded onto the casing 4 and whichbear against disc springs 3. The lower end of the casing 4 carries ablow head 6 which surrounds an elongated sleeve member or filling tube 7which defines an interior filling passage. The blow head 6 is widenedaround the sleeve 7 at its lower end to accommodate a neck of an ampouleor ampoule blank 8a. Theblow head 6 forms the upper part of a blow mold(not completely shown) into which can be injected around the supportingsleeve 7 the ampoule blank 8a which is arranged within an outercylindrical mold container 8b.

In accordance with the invention, a valve member, generally designated9, includes a lowermost end with a valve disc 9a and a verticallyelongated shaft portion or rod 9b. The rod 9b is located within thesleeve 7. It is spaced from the interior wall thereof to provide for aflow passage of the filling liquid.

The cylinder casing 4 includes an intermediate passage portion 5b whichcontinues the liquid inlet flow passage at the upper end of the flowpassage of the sleeve 7 and it connects at its upper end into a widenedarea or inlet chamber 5c having a lateral inlet passage 13 for the inletliquid. 4

The upper end of the valve rod portion 9b is provided with a pin or stopmember 10a located over a guide disc 10b which is guided in thecylindrical widened portion 50. The disc 10b limits the opening strokein cooperation with a case shoulder 11a. A helical spring 112 actsbetween the shoulder llllb and the underside of the disc 10b and iturges the valve member 9 in a direction to close the valve disc 9a.

The filling liquid which is directed into the inlet chamber 13 may flowfrom the widened passage or inlet chamber 50 through openings in thevalve disc 10b and downwardly through the passage 5b to the passage 7afor discharge when the valve disc 9a is in an open position into theblank 8a.

In accordance with a feature of the invention, the inlet chamber 50 isclosed at top by a sealing diaphragm l4 and this diaphragm is clampedtightly between the casing head 15 and the cylindrical casing 4. Thecasing head 15 forms the guide cylinder of a hydraulic or pneumaticcontrol mechanism for operating the valve 9. An operating piston 17b isslidable in a chamber 16b of the casing head 15 and it includes acentral shaft or hub portion 17a which engages over a shank portion ofan adjustable screw 19 carried by the diaphragm 14 and threaded intoshaft 17a of piston 17b. The working fluid inlet 15b is defined in acover 15a of the casing head 15 and a working fluid such as oil or airis admitted through this passage for the purpose of controlling themovement of the piston 17b. The head 15 includes a vent opening or bleed18 to permit displace ment of fluid ahead of the piston 17b during itsdownward movement. The piston is moved downwardly to cause deflection ofthe diaphragm 14 and displacement of the engagement member in the formof a head screw 19 which engages and displaces the pin a and the valve 9downwardly to open the valve by moving the disc 9a off of its associatedseat at the lower end of the sleeve member 7.

The method of operation of the device is as follows:

After the ampoule blank 8a is positioned within the outer container 8band the blank is affixed to the lower end of the blow head 6 around thefilling passage defined by the tubular member 7, the core carrying blank8a is dipped into a blow mold. Then piston 17b is pressed downwardly, bymeans of the head screw 19 for an admission of an operating fluidthrough the chamber b to actuate the piston 17b. This opens the valvedisc 9a and filling liquid is supplied under pressure so that the liquidissuing from the lower end of the passage 70 causes the blowing up ofthe ampoule 8a. After the blowing, some liquid is again withdrawn withthe valve still open. Thereafter, the valve can be closed which iseffected by relieving the piston I 7b to cause spring 12 to urge thevalve rod 9b in an upward direction to close the valve disc 9a.

Since the operating piston 17b and the head screw 19 are not rigidlycoupled with the valve rod, the valve can also be opened by liquidpressure which might appear in the passages 50 and 5b and 7a, but inthis way, damage to the valve can be avoided. By providing the seal ofthe diaphragm 14 to close the inlet chamber 50 from the controlmechanism, there will be no undesired contact of the filling liquid withparts of the control mechanism or its hydraulically operated fluid. Theliquid feed duct of this arrangement is designed for optimum flowwithout any dead angles of admission, and this facilitates the sterilecleaning of the whole device, preferably by blowing it out with a fluidmedium such as steam.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. An arrangement for simultaneously manufacturing and filling a plastichollow body, comprising a cylindrical housing defining an elongatedfilling passage therein and having a lower blow head portion with meansfor holding a hollow blank in alignment with the passage in a positionto be formed and filled by a filling liquid, a valve member displaceablein the passage and including a valve part for opening and closing saidpassage, an inlet defined in said housing communicating with saidpassage, a control mechanism being en' gageable with said valve memberand being operable to cause said valve part to open and close saidpassage, a diaphragm covering said passage upstream of said inlet andsealing said control mechanism in respect to said inlet and being spacedabove said valve member when said valve part is in a closed position,said housing having a casing head of a diameter at least as great assaid diaphragm and engaging said diaphragm in a marginal area around itsperiphery above said inlet in a position to seal off said inlet fromsaid control mechanism, means biasing said valve member in a directionto cause said valve part to close said passage, said control mechanismincluding an actuating member being disposed within said housing andcentrally supporting said diaphragm and being displaceable to move saiddiaphragm to cause it to contact and move said valve member to displacesaid valve part to open said passage.

2. An arrangement according to claim 1, wherein said valve memberincludes a shaft portion, said casing head having a hollow interiorchamber, a piston slidable in said chamber and engageable with saiddiaphragm and comprising said actuating member.

3. An arrangement according to claim 2, wherein said actuating memberincludes an adjusted screw threaded to said piston andbeing adjustablypositionable in respect to said piston for varying the operating strokeof said valve.

1. An arrangement for simultaneously manufacturing and filling a plastichollow body, comprising a cylindrical housing defining an elongatedfilling passage therein and having a lower blow head portion with meansfor holding a hollow blank in alignment with the passage in a posiTionto be formed and filled by a filling liquid, a valve member displaceablein the passage and including a valve part for opening and closing saidpassage, an inlet defined in said housing communicating with saidpassage, a control mechanism being engageable with said valve member andbeing operable to cause said valve part to open and close said passage,a diaphragm covering said passage upstream of said inlet and sealingsaid control mechanism in respect to said inlet and being spaced abovesaid valve member when said valve part is in a closed position, saidhousing having a casing head of a diameter at least as great as saiddiaphragm and engaging said diaphragm in a marginal area around itsperiphery above said inlet in a position to seal off said inlet fromsaid control mechanism, means biasing said valve member in a directionto cause said valve part to close said passage, said control mechanismincluding an actuating member being disposed within said housing andcentrally supporting said diaphragm and being displaceable to move saiddiaphragm to cause it to contact and move said valve member to displacesaid valve part to open said passage.
 2. An arrangement according toclaim 1, wherein said valve member includes a shaft portion, said casinghead having a hollow interior chamber, a piston slidable in said chamberand engageable with said diaphragm and comprising said actuating member.3. An arrangement according to claim 2, wherein said actuating memberincludes an adjusted screw threaded to said piston and being adjustablypositionable in respect to said piston for varying the operating strokeof said valve.